Ideas for sports days

Hi all..This is my second go around and I want to address my issue with sports and IP. My first time, I always had issues when it came to sports as I would sometimes get light headed and fatigued early during tournaments and this caused me to go eat something high in carbs to get my energy back. So, anyone have ideas on how to counter this?? I have a tournament coming up this weekend and I want a game plan for food. I usually pack a cooler to keep me away from the vendor foods, but eating the packs does not cut it. I need food on these types of days, I usually pack veggies, cheeses and meats.. anything with little to no carbs. Any input? thnks!